of, pertaining to, or occurring at the beginning; first: the initial step in a process.
2.
Phonetics. occurring at the beginning of a word or syllable, as the (k) sound of kite, chasm, or quay.
–noun
3.
an initial letter, as of a word.
4.
the first letter of a proper name.
5.
a letter of extra size or an ornamental character used at the beginning of a chapter or other division of a book, manuscript, or the like.
–verb (used with object)
6.
to mark or sign with an initial or the initials of one's name, esp. as a token of preliminary or informal approval.
Origin: 1520–30; < L initiālis, equiv. to initi(um) beginning (init-, n. deriv. of inīre to enter, begin; in-in-2+ īre to go; cf. comes) + -ium-ium) + -alis-al1
Of, relating to, or occurring at the beginning; first: took the initial step toward peace.
Designating the first letter or letters of a word.
n.
The first letter of a proper name.
initials The first letter of each word of a person's full name considered as a unit: stationery monogrammed with her initials.
The first letter of a word.
A large, often highly decorated letter set at the beginning of a chapter, verse, or paragraph.
tr.v.
in·i·tialed also in·i·tialled, in·i·tial·ing also in·i·tial·ling, in·i·tials also in·i·tials To mark or sign with initials, especially for purposes of authorization or approval.
[Latin initiālis, from initium, beginning; see ei- in Indo-European roots.] in·i'tial·ly adv., in·i'tial·ness n.
[i-nish-uh
l] 
adjective, noun, verb, -tialed, -tial⋅ing or (especially British